solves #293: flip game in java

Author: anishLearnsToCode

README.md

@@ -256,7 +256,7 @@
 | 290  | [Word Pattern](https://leetcode.com/problems/word-pattern)                                                                                                             |                                                             [![Java](assets/java.png)](src/WordPattern.java) [![Python](assets/python.png)](python/word_pattern.py)                                                              |                                                                                                                                   |
 | 291  | 🔒 [Word Pattern II](https://leetcode.com/problems/word-pattern-ii)                                                                                                    |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 292  | [Nim Game](https://leetcode.com/problems/nim-game)                                                                                                                     |                                                                 [![Java](assets/java.png)](src/NimGame.java) [![Python](assets/python.png)](python/nim_game.py)                                                                  |                                                                                                                                   |
-| 293  | 🔒 [Flip Game](https://leetcode.com/problems/flip-game)                                                                                                                |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 293  | 🔒 [Flip Game](https://leetcode.com/problems/flip-game)                                                                                                                |                                                                                          [![Java](assets/java.png)](src/FlipGame.java)                                                                                           |                                                                                                                                   |
 | 294  | 🔒 [Flip Game II](https://leetcode.com/problems/flip-game-ii)                                                                                                          |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 298  | 🔒 [Binary Tree Longest Consecutive Sequence](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence)                                                  |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 299  | [Bulls and Cows](https://leetcode.com/problems/bulls-and-cows)                                                                                                         |                                                            [![Java](assets/java.png)](src/BullsAndCows.java) [![Python](assets/python.png)](python/bulls_and_cows.py)                                                            |                                                                                                                                   |

src/FlipGame.java

@@ -0,0 +1,23 @@
+// https://leetcode.com/problems/flip-game
+// N = |currentState|
+// T: O(N^2)
+// S: O(N^2)
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class FlipGame {
+    public List<String> generatePossibleNextMoves(String currentState) {
+        final List<String> result = new ArrayList<>();
+        for (int i = 0 ; i < currentState.length() - 1 ; i++) {
+            if (currentState.charAt(i) == '+' && currentState.charAt(i + 1) == '+') {
+                result.add(flip(currentState, i));
+            }
+        }
+        return result;
+    }
+
+    private static String flip(String state, int index) {
+        return state.substring(0, index) + "--" + state.substring(index + 2);
+    }
+}